Low angle spraying machine



1965 E. R. GILL, JR 3,202,359

LOW ANGLE SPRAYING MACHINE Fild Oct. 23, 1961 2 Sheets-Sheet l FIG.40. FlG.4b. FIG.4c.

INVENTOR. Edwln R. G|I|,Jr. BY

KQRL L0. Hoe/(s ATTORNEY E. R. GILL, JR

Aug. 24, 1965 LOW ANGLE SPRAYING Pf CHINE eetsSheet 2 Filed 001;. 23, 1961 INVENTOR. Edwin R. GilLJr.

KR Rt. E06 KS ATTORNEY United States Patent 3,202,359 LOW ANGLE SPRAYING MACHINE Edwin R. Gill, Jr., Milierton, N.Y., assignor to Karl W. Flocirs, Washington, D.C. Filed Oct. 23, 1961, Ser. No. 146,910 6 Claims. (Cl. 239-1) The present invention relates to spraying machines and has particular reference to low angle spraying machines.

Low angle spraying of roadways or other substantially smooth surfaces involves certain conditions and presents problems which must be met and solved in order to perform the operation successfully.

Of these problems and conditions which are encountered with prior art devices, the character and the shape 'of the spray are probably the most significant. In the device of the present invention it is an object to limit the spread or fan out of the spray to prevent deliberate overlapping. Accidental or momentary overlapping, of course, is often unavoidable but the present invention reduces the overlap to a considerable degree.

In this regard the adjustment that the angle of the spray makes with the pavement is of primary consideration. It is another object of the present invention to relate the angle at which the paint is sprayed to the clearance from the surface being sprayed in order to prevent overlapping of the sprays from the separate spray guns and also to prevent paint from being deposited on the wrong side of irregularities or striae on the sprayed surface.

There is also the orthogonic projection or ground pattern of the spray to be considered which is related to the coverage and which is a sensitive adjustment as will be explained in connection with the figures, in addition to being further related to the road speed of the vehicle carrying the sprayers and the quantity of paint delivered per unit time or distance. i

Accordingly, the present invention is directed to a low angle spraying machinewith minimum overlap of paint from adjacent spray guns through the adjustment of the spray angle to conform to vertical motion of the spray gun mountings.

Other objects and advantages will be apparent from a detailed description of the invention and from the appended drawings and claims.

In the drawings:

FIG. 1 is a side elevational view partly in section of the spraying machine of the present invention mounted on the rear of a vehicle;

FIG. 2 is a top plan view of the spraying machine of the present invention with a plurality of spray guns mounted for use in cooperation with each other;

FIG. 3 is a side elevational view of another embodiment of the spraying machine of the present invention; and

FIGS. 4A, 4B, and 4C show a plan view of the spread of four spray guns for different positions of the spray guns. M

Considering now the details of one of the embodiments illustrated, reference is first made to the partly sectioned side elevational view shown in FIG. 1 and the top view shown in FIG. 2. These show a trailer with a chassis 11 mounted on an axle 12. and a pair of wheels 13. Chassis 11 extends a short distance back of axle 12 and terminates in a cross member 14. Mounted on top 'of chassis 11 is a frame 15 consisting of top and bottom traverse members and as many vertical members as necessary to support upper and lower radius rods 16 and 17, respectively, which are pivoted thereto. Brace 18 is a further support for frame 15.

3,252,359 Patented Aug. 24, 1965 Spray guns 19 are mounted in toboggan-like cradles or stone guards 21. Stone guards 21 are supported by vertical sidepieces 22 to which the free ends ofradius rods 16 and 17 are attached at pivot points 23 and 24, respectively. Spray guns 19 are shown mounted in pairs, two sharing each stone guard assembly but they may also be mounted singly allowing separate stone guards, radius rods, etc. for each spray gun. The eight V-shaped areas 26 show the spread of each spray at approximately 45 overall, which is the maximum permissible fan-out when it is desired to prevent the paint from reaching the opposite side of inequalities on a concrete surface so as not to impair undirectional visibility. That aspect is further discussed in application Serial No. 47,426 of Edwin R. Gill, Jr. filed August 4. 1960 entitled Highway Marketing.

Yoke 27 joining an upper pair of radius rods 16 extends backwardly over terminal cross member 14 and-is fitted with a screw 28 by which means the road clearance of spray guns 19 is adjusted. Adjustment either upward or downward in cooperation with the structure shown does not alter the Width of the ground pattern. Similarly, should the assembly be forced upward by a piece of gravel or stone, or to clear any obstruction, the width of the ground pattern remains fixed. This makes use of the parallel motion linkage.

, In FIG. 1 the stone guard 21, spray gun 19 and radius rods 16 and 17 are shown in solid lines in a lowered position and in dotted outline in a slightly higher position- In this embodiment the radius rod 17 is elongated past pivot point 24, by the extension 29 and is attached to the spray gun 19 by connecting rod 31. Connecting rod 31 may be directly pivoted to spray gun 19 to cause it to pivot about point 32, as shown in FIG. 1, or attached through an adjusting screw, protractor 'or other means whereby a fine setting can be 'made by hand. The embodimentshown in FIG. 3 is raised and lowered through the useof radius rods 34 and 35, yoke 36, and vertical side support 37. Since this embodiment has no extension on the lower radius rod attached to a connecting rod for changing the angular position of the spray gun 38, this angle is adjusted by hand through the movement of spray gun 38 about pivot point 39 gauged by the.protractor arc 40. In this case, the setting on the protractor arc must befor the contemplated height of the spray gun and the spray gun must be reset by hand for all vertical movements of spray gun and stone guard.

It should be noted thatthe width of the ground pattern remains constant through different heights of the spray gun by keeping the distance between the spray gun nozzle and the point at which the spray hits the surface being sprayed a constant distance through the change in angle of the spray gun for each change in height of the spray gun above the sprayed surface. 9

In order to perform the spraying operation as required, the spray gun assemblies must follow the carriage wheels in order to allow the paint to set up and dry'before wheels,

from the vehicle carrying the paint spraying equipment or any other traflic passes over the sprayed area. This neces sitates the mounting of the spray gun assemblies on a backwardly projecting portion of chassis 11, as illustrated in FIGS. 1 and 2. However, the spray gun assemblies should be located as close behind the wheels as practical since any longitudinal rocking of the carriage about the axle as the pivot may cause objectional variation in clearance and coverage of the spray. The length of the carriage forward of the axle should therefore be several times the projection backward. The carriage may be towed behind a truck using a ball and socket, or other hitch, and the attach ment should be made to some part of the truck which is unsprung, such as, for instance, the rear axle. For the same reason the carriage itself is not provided with springs but is resiliently mounted on axle 12 by means of shock absorbers 41. Studs or U bolts 42 clamp the axle 12, and

shock absorbers 41 to chassis 11 as shown in FIG. 1.

FIGS. 4A, 4B and 4C are illustrative of the spread of paint for four adjacent spray guns. FIG. 4A is a diagram of the normal spread of four fans from the spray guns when all the spray guns are positioned as shown in solid lines of FIG. 1. FIG. 4B shows the pattern when a pair of spray guns have'been raised above normal clearance as shown by the position of the spray gun in dotted outline in FIG. 1. Spray patterns 45 are from the spray gun 19 in the raised (dotted) position while patterns 46 are the spray from spray guns 19 positioned as shown by the solid lines of FIG. 1. As can be seen by this illustration, there is no overlap in the spray patterns from the spray gun no matter what their clearance above the surface being sprayed. If a pair of spray guns are raised without the correction in the angle of spray gun 19 about pivot point 32, then the raised spray guns will paint a pattern illustrated by patterns 47 in FIG. 4C. Patterns 48 are from spray guns 19 retained at their normal height. In other words, if the angle of the spray gun 19 remains fixed and is not corrected automatically, as in the embodiment of FIG. 1 or by hand as in FIG. 3, then the center lines of the spray guns will meet the ground surface at a point 50 (FIG. 1) or thereabouts.

In'view of the fact that each unit area of a spray car- .ries, or should carry, substantially equal quantities of paint and that in low angle spraying it is requisite to avoid either too dense a'coverage or a deficiency of coverage, the spray pattern should have a substantially equal cross section'throughout its lateral spread. 1 Any deviation from this will correspondingly result in an excess of paint near the center and a deficiency towards the edges of the pattern, or'vice versa. 7

The importance of the last point is better realized when we consider the orthogonic projection of each unit area or the spray pattern. In an ideal pattern, as a parallelogram for example, the thickness of the sprayed material would be uniform throughout the spread of the pattern, even when the machine is in motion. Due to the limitations of spray guns in general, however,- this ideal is not completely attainable in practice but may be approximated with a properly designed and adjusted spray gun.

.- The nearest approach to the ideal spray pattern thought practical is an elongated ellipse but in such as case the action is somewhat different. In the case of the ideal pattern, only the cross section of the pattern need be considered but where the fan from the nozzle of the spray gun has an oval or elliptical form, the longitudinal dimensions vary, growing shorter outward from the midpoint and therefore the forward travel time becomes more important. If the spray gun were standing still, then every part of the orthogonic projection would receive equal coverage but the spray gun is constantly moving forward at some rate of speed. a I

It has been found preferable not to carry the supply of paint on the trailer or spray machine chassis itself but to locate the tanks on the truck doing the towing. However, a comparatively small regulating tank or tanks may be mounted on the spray machine chassis and supplied from the truck tanks with means provided, such as a float valve or the equivalent, to maintain a constant level and there fore a constant weight and balance thereby not upsetting the height of the'trailer above the .gorund surface and the relationship between the height of the spray gun from be used to adjust the spray guns to prevent overlapping of patterns. The same principles invloved in the previously discussed embodiments apply here.

It should be understood that the specific apparatus shown and described herein is intended to be representative only. Reference should therefore be made to the following claims in determining the full scope of the invention.

What is claimed is: V

1. A low angle spraying machine for spraying a ground surface comprising a wheel mounted chassis including a plurality of wheels, an axle attached to said wheels, and studs and shock absorbers connecting 'said axle to said chassis whereby any springing motion of said chassis is minimized; a frame mounted on said chassis; parallel motion linkage attached to said frame; spraying means positioned vertically by the operation of said parallel motion linkage; and automatic'adjusting means to change ing means in accordance with changes in contour of the ground surface, and automatically adjusting the angle at which the spray'strikes the ground surface in relation to said raising and lowering of the spraying means whereby the distance between the spraying'means nozzle and the point of impingement of the spray on the ground surface remains substantially the same during repositioning of the spraying means by raising and lowering.

3. A method of spraying a ground surface from a low angle which comprises setting a plurality of spray guns on a spraying machine at a height and angle to the ground surface so as to minimize overlapping of the sprays from said spray guns, raising and lowering some ofsaid plurality of spray guns as changes in the contour of the I ground surface are encountered and automatically adjusting the angle at which the spray strikes the ground sur- 7 face in conjunction with the changes in height of each spray gun in order to maintain substantially the same length of the spray from the spray gun to the ground surface for all of said spray guns. 7

4. A low angle spraying'machine for spraying a ground surface comprising a chassis, a frame mounted on said chassis, parallel motion linkage attached to said frame, spraying means positioned vertically by the operation of said parallel motion linkage, a cradle means under said spraying means having a hole through which spray from said spraying means passes whereby protection is afforded the spraying means, and automatic adjusting means to change the angle that the spray from said spraying means makes with the ground surface being sprayed with a change in height of the spraying mea'ns above the ground surface, whereby the angle that the spray from said sprayin g means makes with the ground surface changes in direct relationship to the change in height above the ground surface of said spraying means.

'5. A low angle spraying machine for spraying a ground surface comprising a chassis, a frame mounted on said chassis, parallel motion linkage attached to said frame, spraying means positioned vertically by the operation of said parallel motion linkage, and adjusting means to change the angle that the spray from said spraying means makes with the ground surface being sprayed, said adjusting means comprising an extension arm on said parallel motion linkage, a connecting rod pivotally attached to the free end of said extension arm, and a pivot point at Which said spraying means is attached to said parallel motion linkage, said connecting rod pivotally connected to said spraying means so as to pivot said spraying means about said pivot point at which said spraying means is attached to said parallel motion linkage, whereby the angle that'the spray from said spraying means makes with the ground surface changes in direct relationship to the change in height above the ground surface of said spraying means. 6. A low angle spraying machine for spraying a ground surface comprising a chassis, a frame mounted on said chassis, parallel motion linkage attached to said frame, spraying means positioned vertically by the operation of said parallel motion linkage, and adjusting means to change the angle that the spray from said spraying means makes with the ground surface being sprayed, said parallel motion linkage comprising a vertical section of said frame, a pair of parallel rod-s pivotally attached to said vertical section, a vertical support pivotally attached to each of said parallel rods, said vertical support carrying said spraying means, whereby the angle that the spray from said spraying means makes with the ground surface changes in direct relationship to the change in height above the ground surface of said spraying means.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 2/30 France.

Great Britain.

EVERETT W. KIRBY, Primary Examiner. 15 ROBERT A. OLEARY, LOUIS J. DEMBO,

Examiners. 

1. A LOW ANGLE SPRAYING MACHINE FOR SPRAYING A GROUND SURFACE COMPRISING A WHEEL MOUNTED CHASSIS INCLUDING A PLURALITTY OF WHEELS, AN AXLE ATTACHED TO SAID WHEELS, AND STUDS AND SHOCK ABSORBERS CONNECTING SAID AXLE TO SAID CHASSIS WHEREBY ANY SPRINGING MOTION OF SAID CHASSIS IS MINIMIZED; A FRAME MOUNTED ON SAID CHASSIS; PARALLEL MOTION LINKAGE ATTACHED TO SAID FRAME; SPRAYING MEANS POSITIONED VERTICALLY BY THE OPERATION OF SAID PARALLEL MOTION LINKAGE; AND AUTOMATIC ADJUSTING MEANS TO CHANGE THE ANGLE THAT THE SPRAY FROM SAID SPRAYING MEANS MAKES WITH THE GROUND SURFACE BEING SPRAYED WHEREBY THE ANGLE THAT THE SPRAY FROM SAID SPRAYING MEANS MAKES WITH THE GROUND SURFACE CHANGES IN DIRECT RELATIONSHIP TO THE CHANGE IN HEIGHT ABOVE THE GROUND SURFACE OF SAID SPRAYING MEANS. 